This proposal is for the continuation of a Preventive Intervention Research Center at Arizona State University. The Center seeks to build on a nine year record of scientific accomplishments in prevention research. The Center conducts research on the development and evaluation of preventive interventions for children in three stressful situations which are known risk factors for the development of mental health problems: parental divorce, poverty, and bereavement. For each stressor, the Center conducts an integrated four-phase program of prevention studies. The first phase involves generative (psychosocial theory building) studies to identify modifiable risk and protective factors. The second phase involves developing and pilot testing a preventive intervention program specifically targeted at strengthening these protective factors and reducing risk factors. The third phase involves a rigorous randomized experimental trial of the intervention program to test its effects on children's mental health problems. The fourth phase involves systematic research to design and evaluate methods to diffuse the effective program for widespread delivery to the population. The Center also engages in other activities to build the scientific base for prevention research including: methodology development, theory development, collaborating with prevention researchers at other sites to advance the science of prevention, and training of the next generation of prevention researchers.